hwmon: (ltc4261) Fix error message format

adapter->id is deprecated and not set by any adapter driver, so this
was certainly not what the author wanted to use. adapter->nr maybe,
but as dev_err() already includes this value, as well as the client's
address, there's no point repeating them. Better print a simple error
message in plain English words.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
Cc: Guenter Roeck <guenter.roeck@ericsson.com>
Signed-off-by: Guenter Roeck <guenter.roeck@ericsson.com>